Starter clutch and oil seal therefor



July 4, 1950 C. R. CHERASO EIAL STARTER CLUTCH AND OIL SEAL Filed Oct. 29, 1946 THEREFOR R INVENTORS CHARLES R. CHER/:30 By FORREST A. IERAMPTON ATTORNEY Patented July 4, !95() STARTER CLUTCH Annon. .THEREFOR Applieation0ctober'29, 1946, Serial No. voaiso f' 4 Claims. (Cl. 123-'+179) This invention relates in general to engine starters and more particularly to oil seal means for the prevention of seepage of lubrication oil from the engine crankcase into the casing and operating mechanism of the starter.

In the co-pending application of Ralph M. Heintz, Serial No. 566,871, now abandoned, for Starter Jaw Meshing Mechanism, filed December 6, l944,-is's'hown a new and novel jaw meshing mechanism involving'a rotational drive for the starter jaw and aseparate means includinga spring for eiiecting jaw mesh, which spring, however, is controlled by a spiral lead screw nut maintained in frictional engagement with the starter jaw by the spring to form a cone clutch. In .such anarrangement it is highly important to avoid oil seepage from the engine crankcase into the starter mechanism. Theexistence of oil in the jaw meshing and driving mechanisms under cold temperature conditions results in the congealing of the oil which prevents operation of thestarter jaw driving and extension mechanisms. If oil is present in the cone clutch, or, in other words, between the cone nut and the starter jaw, under hot temperature conditions, the cone clutch slips in spite of the spring so that no jaw extension or jaw mesh can be effected. It is, therefore, one of the primary objects of this invention to provide an oil seal which will positively prevent oil seepage into the starter either around or through the starter jaw.

With the foregoing and other objects in view, the invention resides in the combination of parts and in the details of construction hereinafter set forth in the following specification and appended claims, certain embodiments thereof being shown in the accompanying drawing which is a View of part of an engine starter shown partly in side elevation and partly in longitudinal section to show the starter jaw, the means for rotating the jaw, the means for extending the jaw longitudinally, and the oil seal carried by the starter jaw to include a seal over the end of the hollow starter jaw and a seal carried by the jaw to engage the stationary casing surrounding the jaw and its driving means.

Referring more particularly to the drawings, the stationary casing for the starter is shown at I to include a flange 2 which may be secured by bolts or the like to the crankcase of an engine for cranking purposes. The starter jaw 3 and the two separate means for rotating and for longitudinally shifting the jaw into and out of mesh with the usual complementary engine jaw may be of the same type as disclosed in the copending applicationof Ralph M. Heinz for Starter Jaw Meshing Mechanism, Serial No. 566,871, now abandoned, filed December 6, 1944. Sufiice it to say in-this connection that the hollow starter jaw hub 4-has external longitudinal splines to be engaged by similar internal splines of the driving hub 5 of the planetary gear carrier for rotating the starter jaw by the usual electric motor of the starter.

Shaft 6 is also driven by the starter motor and is provided with spiral lead threads (not shown) to engage similar internal threads on a hollow sleeve '1 which has its outer end flared outwardly and provided with flutes 8 that frictionally engage the inner highly polished smooth bevelled steel surface of the starter jaw. Surrounding the sleeve 1 and inside of. the hollow starter jaw hub 4 is a coil 'spring '9 that is put under initial compression as its one end bears against an internal shoulder ID of the starter jaw and its. other end against a retaining flange H on the sleeve 1. With this arrangement, the engagement of flutes 8 with the starter jaw effects a cone clutch between sleeve 1 and the starter jaw. Thus, a rotation of the starter jaw by driving hub 5 is accompanied by an outward extension of the starter jaw by independent means. That is a rotation of shaft 6 causes the sleeve 1 to rotate and travel outwardly as the spring 9 is forcing the starter jaw 3 outwardly for engagement with the usual engine jaw.

The sealing means for sealing the starter against seepage of oil from the engine crankcase includes a cover plate [2 with flanges [3 that engage a recess in the starter jaw and held there against a packing ring M by a snap ring l5. This insures against oil seepage to the interior of the starter jaw.

For sealing against oil seepage into the starter around the starter jaw there is provided an external sleeve hi secured to be rigid with the starter jaw. This sleeve 46 has a cup I! to house a packing ring l8 that bears on the outside surface of a highly polished stationary steel bushing l9 carried by the starter casing. This makes it impossible for any oil to seep into the starter around the starter jaw, because even if oil surrounds the sleeve H6 or gets behind it, the packing ring l8 prevents any oil from entering the starter. In order to insure against oil leakage or seepage it is preferable that packing rings [4 and I8 be made of neoprene, or other equivalent oil resistant characteristics.

Thus from the foregoing it will be seen that there has been provided a simple and efiicient oil sealing means which effectively seals against any oil seepage from the engine crankcase into the starter or from the starter into the engine crankcase either through or around the starter jaw.

, Moreover, such an oil seal in no way interferes with the rotational drive or the extension and retraction or the jaw meshing mechanism for ehgine cranking.

We claim:

1. In a direct cranking engine starter adapted aw independently of said jaw extension means to for releasable extension into an engine Erai'ik case and having a hollow starter jaw for engaging 5 an engine jaw for cranking, jaw rotating means outside of said jaw and splined thereto for di;

rect drive, independent reSil-ientjaW extension from said crankcase to the interior of said starter through said hollow jaw, said sealing means comprising a cover plate removably secured to the outside of said jaw independently of said jaw ex tension means to cover the central opening and the jaw meshing means therein; 2. In a direct cranking engine starter adapted for releasable extension into an engine crankcase and having a hollow starter jaw for engaging an engine jaw for cranking, jaw rotating means outside of said jaw and splined thereto for direct drive independent .jaw extension means in said hollow jaw, and an oil sealing means for-preventing oil seepage from said engine crankcase to the inside of said starter and from 'said starter to said crankcase about the exterior of said starter jaw comprising a sleeve carried by said starter jaw and carrying a packing ring slid'ably engaging a stationary part of said starter housing surrounding the hub of said starter jaw.

3. In a direct cranking engine starter adapted [it means and. automatic cone clutch. regulating means therefor in said hollow jaw, and an oil sealing means for sealing against seepage of oil for releasable extension into an engine crankcase and having a hollow starter jaw for engaging an engine jaw for cranking; jaw rotating means outcover the central opening.

W 4-. In a direct cranking engine starter adapted for releasable extension into an engine crankcase and havinga hollow starter jaw for engaging an engine aw for cranking, aw rotating means outside of said jaw and splined thereto for direct drive, independent resilient jaw extension means and automatic cone clutch regulating means therefor in said hollow jaw, an oil sealing means for sealing against seepage of oil from said crankcase to the interior of said starter through said hollow jaw, said sealing means comprising a cover plate removably secured to the outside of said jaw independently of said jaw extension means to cover the central opening, oilsealing means for preventing oil seepage'from said engine crank case to the inside of said starter and from said starter to said crankcase aboutthe exterior of said starter jaw comprising a sleeve carried by said starter jaw and carrying a packing ring slidably engaging a stationary bushing of said starter surrounding theliub or said starter jaw.

CHABLE$ R, CHER-A59. FORREST A. FR-AMPTON.

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